Lubricating gun



Nov. 11, 1930. Y J. E. M. SEGUIN LUBRICATING GUN Filed Sept. 24, 1929 Patented Nov. 11, 1930 UNITED STATES JULIEN EUGNE MARIUs SEGUIN, oryrnnrs, FRANCE LUBRICATING GU'iv Application filed september 24, 1929, seriai @$394,913 and 11i' Frankie october e, 192s.

My invention relates to improvements in high pressure grease guns, and the general object of the invention is to provide a device of the type described which gives, with minimum muscular energy, a pressure surpassing considerably that which is possible to obtain Vwith similar apparatuses of the screw type known in the prior art.

My improved gun is provided with a pump 1Q body and a piston furnished with a threaded rod screwing into the closing cap of the pump body and is characterized by the fact that the threaded rod of the piston is tubular and a small high pressure piston is slidably 15 dis osed on said rod.

ne improvement resides in the fact that the rod of the small high pressure piston slides through a nut, in which said rod is locked in the direction of rotation whereas the said nut is screwed in the upper tapped part of the tubular rod of the large piston.

My invention will be more readily understood by those skilled in the art to which my invention relates in the followingV description taken in connection with the accompanying drawing in which Fig. 1 is an axial section taken through my improved pump; and

Fig. 2 is a section along the line 2-2 of Fig. 1.

Referring to the drawing more in detail, the cylindrical pump body (a) is closed at its upper part by a cap b screwed thereon. The rod c of the large piston Z is screwed into a central boss e of the cap o. Said rod is threaded with a high pitch thread. The internal wall f of the cap b is of a diameter equal to that of the pump body a. The height of said wall issuoh that the piston d may be lodged therein during filling of the body a. Such disposition eliminates introduction of piston d in the body a after filling thereof.

The threaded rod c is tubular so as to constitutea small pump body in the interior of which slides a small piston g. Said small 'piston is extended by a rod Y71, surmounted by a handle z'. A handle j is also mounted on the threaded rod 0 for manipulating the large piston d.

- Thefupper-tubular part of the rod c is tapped Vat la over a certain distance. A- nut --Z is screwed into said tapped portionandis apertured centrally.4 kSaid nut is traversed 'by-the rod it ofthe small piston'and pro- 55 .vided with a key m sliding in a groove n providedr in the rod of the small piston.

The' largevpistonjd is leather covered'or fittedwith any other flexible material prorviding goodfcompression. The assembly of co leatherandgwashers composing the piston is fixed on the rod 'c by means o f ya guardo of steel wire,.. lodged'in a groove p provided at `vthe base of the rrod c. A Vwasher g-having a taperedbore prevents any accidental tear- 'ing offxofthe; guard o; p `A nipple r closes the'upper'partv of the tubular rod c and maintains vthe rod z, ofthe small piston g. The operationv of the gun is as follows:

The pump body a being filled with lubri- To \cant,-it is-merely necessary, after having put the cap b in plate, to turn the rod 101 in the Y boss e; Thev piston d, by descending, automatically takes its place in the pump body and compresses the lubricant with which it: enters into contact. Said lubricant pushed into the interior ofthe tubular rod c shoves the small piston g to the ,end of its stroke. All thrust produced from that moment on on the handle z' of said small piston deter-:58o mines on the interior of the pump body a pressure -which can attain a considerable value, varying in accordance with the thrust l and the surface of the small piston. In fact, the pressure obtained for a given force beingiss inversely proportional to the surface-of the piston, said pressure will be as much greater as the surface of piston g is made smaller.

It is to benoticed that due to this disposition, the small piston g is always shoved backfrf'o in readiness by the shoving back of the lubricant without the` aid of any returnspring. In addition, I eliminate any suction and consequently all vacuum on the interior of the apparatus which as a result does away within checks and prevents unpriming and other entry of air injurious to good lubricating. operations.

When the lubricating is `possible with direct pressure on the small pistomsubsequentilo to the plugging up of a grease' cup or for other rea-sons, it sulices then to unscrew the rod h by means of its handle z'. This Inovement is communicated by the groove n and the keyv m to the nut Z. Said nut, by screwing in the tapped part 7c of the tubular rod 0 bears on the piston g. The lubricant then becomes subjected to an enormous pressure which allows lubrication to be eiected un der all conditions.

Having described my invention what I claim as new and desire to secure by Letters Patent is: Y

l. A lubricating inrcomprising a pump body, a piston slidab y mounted in said body, a hollow piston rod for said piston, a second smaller piston slidably mounted in said rod, means for manually reciprocating said smaller piston including a piston rod, and a nut screwed into said first piston rod feathered to said second piston rod and having means for abutting said smaller piston at the end4 of its stroke when said pistonfrod is rotated.

2. A lubricating gun comprising a pumpk body, apiston slidablyk mounted in said body, a hollow piston rod for said piston, a second smaller piston slidably mounted in said rod,

means for manually reciprocating said small- 4 er piston including a *piston rod, a nut screwed into said first piston rod, and a key Von said nut adapted to engage a keyway in said second named piston rod, said nut having means for abutting said smaller piston at theend of its stroke when said piston rod is rotated.

In testimony whereof I hereunto ax my signature. 4

JULIEN EUGNE MARlUS SEGUIN. 

